TCSC

The development of the modern power system has led to an increasing complexity in the study of power systems, and also presents new challenges to power system stability, this study investigates the improvement of power flow control and oscillation damping, by using TCSC and SSSC which is an effective FACTS device. Power system oscillation has been recognized as one of the major concerns in power system operation. Simulations are carried out in Matlab/Simulink environment to evaluate the effectiveness of Fixed Capacitor (FC), Thyristor Controlled Series Capacitor (TCSC), and Static Synchronous Series Compensator (SSSC) on three-machine power systems. The performance of TCSC is compared with FC and other FACTS devices such as Static Synchronous Series Compensator (SSSC).The simulation results show that in damping power system oscillations, the SSSC is more effective than TCSC and FC. In addition, the implementation of TCSC and SSSC to control the flow of power in apart of Libyan 220Kv ring around Tripoli center and specifically to reduce the loading of highly loaded transmission line in this network is presented.

In recent years, power demand has increased substantially while the expansion of power generation and transmission has been severely limited due to limited resources and environmental restrictions. As a consequence, some transmission lines are heavily loaded and the system stability becomes a power transfer-limiting factor. Flexible AC transmission systems (FACTS) controllers have been mainly used for solving various power system steady state control problems. However, recent studies reveal that FACTS controllers could be employed to enhance power system stability in addition to their main function of power flow control. The literature shows an increasing interest in this subject for the last two decades, where the enhancement of system stability using FACTS controllers has been extensively investigated. This paper presents a comprehensive review on the research and developments in the power system stability enhancement using FACTS damping controllers. Several technical issues related to FACTS installations have been highlighted and performance comparison of different FACTS controllers has been discussed. In addition, some of the utility experience, real-world installations, and semiconductor technology development have been reviewed and summarized. Applications of FACTS to other power system studies have also been discussed. About two hundred twenty seven research publications have been classified and appended for a quick reference.

— In recent years, much attention has been attracted to the problems of voltage quality for the electrical power systems. Because of continuous increase of power demands and large scale system interaction as well as the consideration of both the economic benefit and the environment protection, modern power system are operated more and more close to the their maximum operating conditions. As a consequence, some transmission lines are heavily loaded and the system stability becomes a power transfer-limiting factor. In these days, voltage of the system can be control in many ways and the latest technology by using power electronic device that we call as FACTS-devices. Flexible Ac Transmission System (FACTS) devices are the option to mitigate voltage instability by reactive power flow and voltage control criteria. It has lot of configuration like series, shunt etc. TCSC is series type and STATCOM is shunt type controller. In this paper both the devices are compared for voltage stability enhancement.

The development of the modern power system has led to an increasing complexity in the study of power systems, and also presents new challenges to power system stability, and in particular, to the aspects of transient stability and small-signal stability. So Power system engineers are currently facing challenges to increase the power transfer capabilities of existing transmission system. This is where the Flexible AC Transmission Systems (FACTS) technology comes into effect with relatively low investment, compared to new transmission or generation facilities. Flexible AC transmission system (FACTS) devices use power electronics components to maintain controllability and capability of electrical power system. The paper aims towards the performance of UPFC is compared with other FACTS devices such as Static Synchronous Series Compensator (SSSC), Thyristor Controlled Series Capacitor (TCSC), and Static Var Compensator (SVC) respectively. The simulation results demonstrate the effectiveness of the UPFC on transient stability of the system.

With the help of FACTS devices, it is possible to regulate real and reactive power flow in the network. In this paper , in order to incorporate these devices a modification on the existing load flow is carried out. Newton-Raphson technique is used to carry out the load flow programming. The load flow results are then used for the study the effectiveness of these devices. Also a comparative study on the different types of devices(devices with different specifications )are done.

The increase of power system demand leads to the change in voltage profile, reliability requirement and system robustness against disturbance. The voltage profile can be improved by providing a source of reactive power through the addition of new power plants, capacitor banks, or implementation of Flexible AC Transmission System (FACTS) devices such as Static VAR Compensator (SVC), Unified Power Flow Control (UPFC), Thyristor Controlled Series Capacitor (TCSC), Thyristor Controlled Phase Shifting Transformer (TCPST), and many others. Determination of optimal location and sizing of device injection is paramount to produce the best improvement of voltage profile and power losses reduction. In this paper, optimization of the combined advantages of TCPST and TCSC has been investigated using Particle Swarm Optimization (PSO) algorithm, being applied to the 30-bus system IEEE standard. The effectiveness of the placement and sizing of TCPST-TCSC combination has been compared to the implementation of capacitor banks. The result showed that the combination of TCPST-TCSC resulted in more effective improvement of system power losses condition than the implementation of capacitor banks. The power losses reduction of 46.47% and 42.03% have been obtained using of TCPST-TCSC combination and capacitor banks respectively. The TCPST-TCSC and Capacitor Bank implementations by using PSO algorithm have also been compared with the implementation of Static VAR Compensator (SVC) using Artificial Bee Colony (ABC) Algorithm. The implementation of the TCSC-TCPST compensation with PSO algorithm have gave a better result than using the capacitor bank with PSO algorithm and SVC with the ABC algorithm.

In recent years, power demand has increased substantially while the expansion of power generation and transmission has been severely limited due to limited resources and environmental restrictions. Transient stability control plays a significant role in ensuring the stable operation of power systems in the event of large disturbances and faults, and is thus a significant area of research. Flexible AC transmission systems (FACTS) controllers have been mainly used for solving various power system steady state control problems. FACTS devices are capable of controlling the active and reactive power flows in a transmission line by controlling its series and shunt parameters. This paper presents a review of comparison of different FACTS controllers in the power system for stability enhancement. Benefits of FACTS controllers to power system are also discussed.

The paper presents the development of a PQ theory based on control system for the Thyristor Controlled Series Capacitor (TCSC). In distribution networks for active filter control instantaneous PQ theory has been successfully used. In this scheme, system response is very fast to reduce the response time, which allows instantaneous control in the line power flow. Using ATP-EMTP simulated results were obtained for different operating conditions.

In this paper, voltage stability assessment with appropriate representations of STATCOM, TCSC and SSSC is investigated and compared in the modified IEEE 14-bus test system. AC and DC representations of STATCOM, TCSC and SSSC are used in the continuation power flow process in static voltage stability study. The appropriate representation provides more practical solutions in the dc parts of these devices. Static voltage stability margin enhancement using STATCOM, TCSC and SSSC is compared in the modified IEEE 14-bus test system.

Power system stability problem has always received a great deal of attention. Recent development of power electronics introduces the use of Flexible AC Transmission Systems (FACTS) controllers in power systems. FACTS controllers are capable of controlling the network condition in a very fast manner and this feature of FACTS can be exploited to improve the stability of a power system. Thyristor Controlled Series Capacitor (TCSC) is a prominent series FACTS controller which is very useful for power flow control. This project proposes to develop a robust Fuzzy Logic based TCSC controller to improve stability. For simulation purpose, the model of single-machine infinite bus (SMIB) power system with TCSC controller is developed in MATLAB/SIMULINK. The simulation results show that the proposed TCSC controller is effective in damping a range of large disturbance conditions in the power system and thus improving the stability of the system.

This paper proposes Improving of ATC is an important issue in the current de-regulated environment of power systems. The Available Transfer Capability (ATC) of a transmission network is the unutilized transfer capabilities of a transmission network for the transfer of power for further commercial activity, over and above already committed usage. Power transactions between a specific seller bus/area and a buyer bus/area can be committed only when sufficient ATC is available. Transmission system operators (TSOs) are encouraged to use the existing facilities more effectively to enhance the ATC margin. Heavily loaded circuits and buses with relatively low voltages can limit ATC usually. It is well known that FACTS technology can control voltage magnitude, phase angle and circuit reactance. Using these devices may redistribute the load flow, regulating bus voltages. Therefore, it is worthwhile to investigate the impact of FACTS controllers on the ATC. In this thesis focuses on the evaluation of the impact of TCSC and SVC as FACTS devices on ATC and its enhancement during with and without line outage cases. In a competitive (deregulated) power market, optimal the location of these devices and their control can significantly affect the operation of the system and will be very important for ISO.

Advent in power electronics enhanced the dynamic performance of modern power
system and Flexible AC Transmission Systems (FACTS) provided vital solution for it.
FACTS are basically thyristor-controlled devices which control the active and reactive
power flow in the network and are equally adaptive to voltage magnitude control thus,
utilize the existing power network optimally. But increase in complexity, configurations
and total power transmitted lead to a number of problems in relation to transmission
line protection. The most widely used protection system in case of high voltage and extra
high voltage transmission lines is Distance protection. However, installation of series
compensation system creates problems for protective relays and fault locators due to
change in the magnitudes and directions of fault voltages and currents in the networks
and causes malfunctioning of the distance relay. Since protection of transmission lines
plays crucial role in improving the stability and reliability of electric power systems,
this paper also throws light on the impact. MATLAB/SIMULINK is used effectively in
modelling and simulation of distance relay as well as transmission line compensated
with thyristor-controlled series compensator. The simulation results illustrate the
effective use of MATLAB/SIMULINK in understanding the behaviour of distance relay
in protecting the transmission lines with and without compensation.

As the world is progressing forward, the load demand in the power system has been continuously increasing day by day. This situation has forced the power system to operate under stress condition due to its limitation. Therefore, due to the stressed condition, the transmission losses faced higher increment with a lower minimum voltage. Theoretically, the installation of the Flexible AC Transmission System (FACTS) device can solve the problem experienced by the power system. This paper presents the Whale Optimization Algorithm for loss minimization using FACTS devices in the transmission system. Thyristor controlled series compensator (TCSC) is chosen for this study. In this study, WOA is developed to identify the optimal sizing of FACTS device for loss minimization in the power system. IEEE 30-bus RTS was used as the test system to validate the effectiveness of the proposed algorithm.

In recent years, power demand has increased substantially while the expansion of power generation and transmission has been severely limited due to limited resources and environmental restrictions. Transient stability control plays a significant role in ensuring the stable operation of power systems in the event of large disturbances and faults, and is thus a significant area of research. Flexible AC transmission systems (FACTS) controllers have been mainly used for solving various power system steady state control problems. FACTS devices are capable of controlling the active and reactive power flows in a transmission line by controlling its series and shunt parameters. This paper presents a review of comparison of different FACTS controllers in the power system for stability enhancement. Benefits of FACTS controllers to power system are also discussed.

Power loss reduction, improvement of voltage profile, system reliability and system security are the important objectives that motivated researchers to use custom power devices/FACTS devices in power systems. The existing power quality problems such as power losses, voltage instability, voltage profile problem, load ability issues, energy losses, reliability problems etc. are caused due to continuous load growth and outage of components. The significant qualities of custom power devices /FACTS devices such as power loss reduction, improvement of voltage profile, system reliability and system security have motivated researchers in this area and to implement these devices in power system. The optimal placement and sizing of these devices are determined based on economical viability, required quality, reliability and availability. In published literatures, different algorithms are implemented for optimal placement of these devices based on different conditions. In this paper, the published literatures on this field are comprehensively reviewed and elaborate comparison of various algorithms is compared. The inference of this extensive comparative analysis is presented. In this research, Meta heuristic methods and sensitive index methods are used for determining the optimal location and sizing of custom power devices/FACTS devices. The combination of these two methods are also implemented and presented.

Power system is subjected to sudden changes in load levels. Stability is an important concept which determines the stable operation of power system. In general rotor angle stability is taken as index, but the concept of transient stability, which is the function of operating condition and disturbances deals with the ability of the system to remain intact after being subjected to abnormal deviations. A system is said to be synchronously stable (i.e., retain synchronism) for a given fault if the system variables settle down to some steady-state values with time, after the fault is removed.

To aid the decision maker, the optimal placement of FACTS in the electrical network is performed through very specific criteria. In this paper, a useful approach is followed; it is based particularly on the use of Kalai-Smorodinsky bargaining solution for choosing the best compromise between the different objectives commonly posed to the network manager such as the cost of production, total transmission losses (Tloss), and voltage stability index (Lindex). In the case of many possible solutions, Voltage Profile Quality is added to select the best one. This approach has offered a balanced solution and has proven its effectiveness in finding the best placement and setting of two types of FACTS namely Static Var Compensator (SVC) and Thyristor Controlled Series Compensator (TCSC) in the power system. The test case under investigation is IEEE-14 bus system which has been simulated in MATLAB Environment.

— Power system stability is a major concern due to complexity in modern power system. This complexity occur due to the large number of interconnection, installation of new generating units etc. In this work, consider the multi machine power system installed with conventional PI based and Fuzzy based Thyristor Controlled Series Compensator (TCSC) controller respectively. In order to test effectiveness of these controller results are carried out for different type of faults i.e. L-G fault and LLL-G fault. The performance of Fuzzy based TCSC controller is compared with that of conventional PI based TCSC controller. It shows that the proposed fuzzy based TCSC controller is very effective and outstanding operation in fast damping of power system oscillations and hence enhance the stability of given system.

This paper proposes a residue factor method to obtain the optimal location of the Thyristor Controlled Series Capacitor (TCSC) device to damp out the inter-area mode of oscillations. The residue method is base on the facts that it is the product of the mode’s Observability and controllability index of TCSC controllers to the critical mode. The placements of TCSC controllers have been obtained for the base case and for the dynamic critical contingences. Eigen value analyses are used to assess the most appropriate input signals (stabilizing signal) for supplementary damping control of TCSC. The Right-Half Plane zeros (RHP-zeros) and Hankel Singular Value (HSV) is used as tools to select the most receptive signal to a mode of the Interarea oscillation. The effectiveness of the proposed method of placement is demonstrated on practical network of 25 bus south Malaysian Power system.

The process of selecting optimal settings for directional over-current relays (DOC relays) is a selection of time dial setting (TDS) and IP (backup current), So that changes in the system of electrical power distribution. In this work, a breeder genetic algorithm (BGA) has been applied to optimal settings of DOC relays with multisystem D-FACTS devices. The simulation consists of two network operation scenarios, scenario without D-FACTS which consisting of coordination of DOC relays against three phase faults, and the second scenarios with multi TCSC. In general, had been verified on optimal settings of relays that the impacts of TCSC insertion in 33-bus distribution system on DOC relays.

In this paper, voltage stability assessment with appropriate representations of STATCOM, TCSC and SSSC is investigated and compared in the modified IEEE 14-bus test system. AC and DC representations of STATCOM, TCSC and SSSC are used in the continuation power flow process in static voltage stability study. The appropriate representation provides more practical solutions in the dc parts of these devices. Static voltage stability margin enhancement using STATCOM, TCSC and SSSC is compared in the modified IEEE 14-bus test system.

The process of selecting optimal settings for directional over-current relays (DOC relays) is a selection of time dial setting (TDS) and IP (backup current), So that changes in the system of electrical power distribution. In this work, a breeder genetic algorithm (BGA) has been applied to optimal settings of DOC relays with multisystem D-FACTS devices. The simulation consists of two network operation scenarios, scenario without D-FACTS which consisting of coordination of DOC relays against three phase faults, and the second scenarios with multi TCSC. In general, had been verified on optimal settings of relays that the impacts of TCSC insertion in 33-bus distribution system on DOC relays.

The development of the modern power system has led to an increasing complexity in the study of power systems, and also presents new challenges to power system stability, this study investigates the improvement of power flow control and oscillation damping, by using TCSC and SSSC which is an effective FACTS device. Power system oscillation has been recognized as one of the major concerns in power system operation. Simulations are carried out in Matlab/Simulink environment to evaluate the effectiveness of Fixed Capacitor (FC), Thyristor Controlled Series Capacitor (TCSC), and Static Synchronous Series Compensator (SSSC) on three-machine power systems. The performance of TCSC is compared with FC and other FACTS devices such as Static Synchronous Series Compensator (SSSC).The simulation results show that in damping power system oscillations, the SSSC is more effective than TCSC and FC. In addition, the implementation of TCSC and SSSC to control the flow of power in apart of Libyan 220Kv ring around Tripoli center and specifically to reduce the loading of highly loaded transmission line in this network is presented.

Transmission congestion is mainly caused by agreed transactions between generating companies and distributing companies in deregulated power system networks across the world. Secured and safe operation of power system networks in the deregulated scenario can be ensured by managing the congestion in the lines. FACTS devices are used for changing the power flows so that all the lines are carrying power below their respective limit. In this work, series connected Thyristor Controlled Switched Capacitor(TCSC) devices are installed in suitable lines for relieving congestion in the over loaded lines of the system. The size and location of TCSC devices greatly affects their efficiency in congestion management problem. To maximize the benefits of TCSC in congestion management problem, the site and size of the TCSC devices are optimized by using an optimization technique. The recent bio inspired Whale Optimization Algorithm (WOA) is employed in this proposed work for the optimization of the objective value through identifying the position and size of FACTS devices. This algorithm involves less number of parameters to be tuned for attaining global best results and can be easily coded in Matlab platform. The proposed WOA based method for optimal sizing and sizing of TCSC is implemented on the IEEE 30 bus test system. The results obtained are compared against the results reported by Particle Swarm Optimization algorithm (PSO), Firefly algorithm(FFA)and are found to be outperforming.